Splinter looks and listens behind them before giving the door to the office a close inspection. Kicking it down is always an option, but it's a last resort given how much noise that would make. And while he knows he could likely get out in time before they're discovered, he doesn't know if Sallie is up to that particular challenge.

But...there's a lock on the outside. That's promising.
He reaches up one of his sleeves and retrieves a lock pick set, and quickly sets to work picking apart the tumblers.

Meanwhile in the back ground there's the low timber of Raph's voice trying to talk reason to the heavily armed men currently holding him at gun point. Then there's the higher pitched sounds of the police being taken by surprise. Perhaps a further gunshot or two.